Bangalore Metro Rail Corporation — negligence in providing exact change

Today took a commute from byapnahalli metro station to national college, as the fare was 35/-, rs100 was paid by me. What i get is rs 40/- in return when enquired, the chasier shows the cash drawer, is this how they are trained to behave with the commuters, it's not the first time this had happened before too. Will you be okay and provide the token if i hadn't paid the exact fare. Do have some responsibility smh.